[CO #5,6] Cover MainNewStreetcode component with unit tests

[mykola-krai]

Write unit test for creating a streetcode component:

• test for creation with only all required fields
• test for creation with all possible fields and entities
• load image and audio from project assets (create a folder for_tests if not exists). Use both small and large images with .webp format
• check if correct entity was sent to backend

Write unit test for updating a streetcode component:

• check if all data that was accepted from mocked get request was set in corresponding fields

Mock all needed request to backend such as Create image request and others